
Keywords: FISE; fluoride ion-selective electrode; TISAB; total ionic strength adjusting buffer; EDTA; ethylenediaminetetraacetic acid disodium salt; CDTA; 2-[2-[bis(2-hydroxy-2-oxoethyl)amino]cyclohexyl]-(2-hydroxy-2-oxoethyl)aminoethanoic acid; EC; external calibr